The invention relates generally to connector systems for insulated concrete wall panels and, more specifically, to a symmetrical load transfer connector for use in precast insulated concrete wall panels.
Precast insulated concrete wall panels are well known in the art and offer a number of advantages for residential and commercial building construction. These advantages include shorter construction schedules, improved thermal resistance, improved quality control, and enhanced durability. However, conventional concrete wall panels are heavy, thus increasing the cost of transporting the panels from the precasting plant to the job site. The large weight of the panels often times requires multiple loads to be delivered to the job site, thereby resulting in potential delays during loading, transportation, and unloading. The large weight also requires the use of an expensive, heavy crane for panel installation.
Insulated concrete wall panels may include inner and outer concrete layers, or wythes, with an internal insulation layer provided between the concrete layers, so as to be lighter weight than solid walls of the same thickness. The prior art concrete wall panels are typically constructed using metallic connectors with high thermal conductivities. Plastic connectors have been used to reduce thermal bridging and problems with corrosion of the metallic connectors, but have problems due to long-term creep and quality due to manufacturing processes. Another connector system uses transverse layers of fiber rovings. However, these connectors result in weak points in the wall panels and are subject to inner laminar shear resulting in brittle failure of the connection system.
To improve the composite character of insulated wall panels, while avoiding the solid concrete sections and metallic connectors which created thermal bridges across the wythes and reduce the insulation factor of the panels, connectors made of high-strength composite materials, such as resin-boded glass fibers, have come into use. These materials do not suffer from the long-term creep of plastic connectors and are resistant to the laminar shear that causes failure of the layered roving connectors.
The connector of the present invention has low thermal conductivity to prevent thermal bridging and is of a symmetric shape which allows the formed wall panels to resist forces induced during manufacturing, transportation and installation of the wall panel and environmental forces induced on the wall panel after installation.
Accordingly, a primary objective of the present invention is the provision of an improved connector system for insulated concrete wall panels.
Another objective of the present invention is the provision of an improved concrete wall panel.
A further objective of the present invention is the provision of a symmetrical insulating connector for interconnecting two or more concrete layers of a concrete panel and which is adjustable to accommodate sandwiched insulation layers of a range of thicknesses.
These and other objectives become apparent from the following description of the invention.